Cellular communication systems are multi-user, wireless communication systems capable of concurrent use by large numbers of users. These systems may be packet wireless communication systems providing voice and other real time communications between mobile terminals operable in such a system. Advancements in communication technologies have permitted the development and popularization of new types of mobile devices for use with cellular communication systems. Multi-function mobile communication systems are exemplary of systems made possible as result of such advancements.
In order to ensure the validity of a user of such a system, authentication procedures are carried out to ensure that traffic between the server of the network portion of the system and a mobile device is sent to an intended recipient. Subsequent to authentication, communications are permitted between a mobile device and the server of the network portion of the system.
Recently however, with the advancing sophistication of mobile devices in general, there is an ever-increasing array of services available which may be provided on mobile devices, including cellphones, PDAs and the like. However, authentication procedures used to protect these services have not similarly advanced to match the sophistication of today's mobile devices. Current mobile devices are still authenticated for the most part by a single authentication parameter such as the entry of a pass code used to “unlock” the device, providing an “all or nothing” approach for mobile device authentication.
Given that the data and services provided by the mobile device vary in importance to a user, and given that authentication procedures will ordinarily be more or less cumbersome based on the level of security they provide, what is needed is a system of authentication offering a tradeoff between these two ideals by tailoring authentication procedures to individual services offered on a mobile device.